To find your CentOS version and architecture, you can use the following easy commands.

1. Quick and easy command to show what version and architecture your CentOS server is running:

$ echo "I am running: `cat /etc/redhat-release` (`arch`)"
I am running: CentOS release 5.8 (Final) (x86_64)

 2. Show CentOS version using /etc/issue:

$ cat /etc/issue
CentOS release 5.8 (Final)

 3. Show CentOS version using /etc/redhat-release:

$ cat /etc/redhat-release
CentOS release 5.8 (Final)

 4. Show CentOS architecture using the arch command:

$ arch
x86_64

 5. Show runnel kernel version and architecture with the uname command:

$ uname -r -v -p
2.6.18-308.el5.028stab099.3 #1 SMP Wed Mar 7 15:56:00 MSK 2012 x86_64